An electric motor of an electrical household appliance operates as an energy transducer, which converts electric energy to mechanical energy. The electric energy supplied to the electric motor is controlled through a semiconductor power device such as a TRIAC (Triode for Alternating Current) or a MOSFET (metal-oxide-semiconductor field-effect transistor). When the load to the electric motor changes, especially when the electric motor runs at a low speed and under a heavy load condition, the motor may generate too much heat and sometimes the motor can be burned due to the heating efficiency positive feedback. A conventional way to address this problem is to add a thermal fuse to protect the motor from being burned. Another conventional way to address this problem is to add a resettable fuse to avoid the motor damage. However, both of the conventional ways have disadvantages. Adding a thermal fuse can prevent the motor from being burned but can not avoid the motor damage. To add a resettable fuse can avoid the motor damage but the cost is quite high.